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On October 14, 2016, the United States Court of Appeals for the Federal Circuit (“Federal Circuit”) affirmed a claim construction in Poly-America, L.P. v. API Industries, Inc., No. 2016-1200, slip op. at 2 (Fed. Cir. Oct. 14, 2016) that resulted in complete non-infringement. The case is yet another reminder that claim scope is hotly contested in patent enforcement efforts and should be carefully protected. Notably, the claim construction at issue relied heavily on the patent specification itself and only slightly on prosecution history. Thus, protection of claim scope starts from the inception of patent application drafting.

THE DISTRICT COURT CASE

Poly-America, L.P. (“Poly-America”) owns U.S. Patent No. 8,702,308 (“’308 Patent”), which is directed to elastic drawstring trash bags.[1] The ’308 Patent issued on April 22, 2014, and Poly-America filed suit on May 13, 2014 in the United States District Court for the District of Delaware (“district court”), accusing API Industries, Inc. (“API”) of infringement of claim 10 of the ’308 Patent.[2]

The principle feature at issue in the case was the “short seal” claimed in the ’308 Patent.[3] In the ’308 Patent, the short seal is indicated by numeral 120, which extends inwardly from the side seal of the trash bag, as indicated by numeral 106.[4] In prior art trash bags, the short seal was aligned with the side seal and did not extend inwardly.[5]

(’308 Patent, FIGS. 3, 4.)

The narrowed opening due to the short seal of the ’308 Patent allows the trash bag to more securely wrap around the rim of a trash receptacle.[6]

Poly-America asserted claim 10 of the ’308 Patent (reproduced below):

An elastic drawstring trash bag comprising:

a polymeric bag comprised of a first panel and a second panel, the first panel and the second panel joined at a first side, a second side, and a bottom,

a first hem formed in the first panel, the first hem having a first elastic drawstring disposed therein,

a second hem formed in the second panel, the second hem having a second elastic drawstring disposed therein,

the first panel, the first elastic drawstring, the second panel, and the second elastic drawstring inseparably joined together at a first short seal and at a second short seal, and

a first access cutout along the upper edge of the first panel and a second access cutout along the upper edge of the second panel, the first and second elastic drawstrings being accessible through the respective first and second access cutouts.

Like other claims of the ’308 Patent, claim 10 requires a short seal.[7] However, unlike other claims of the ’308 Patent, the express language of claim 10 does not require a narrowed opening.[8] The accused API trash bags also did not have a narrowed opening,[9] which may explain why Poly America asserted only claim 10 of the ’308 Patent.

Based on the patent specification and prosecution history, the district court construed the term “short seal” as “a seal for securing the elastic drawstring, which seal is located adjacent to a side seal, and that is not substantially aligned with the side seal, but extends inwardly from the interior edge of the side seal.”[10] Under the district court’s construction of short seal, API did not infringe claim 10 because API’s accused bags had short seals that were substantially aligned with the side seal and did not extend inwardly.[11] Thus, Poly-America stipulated to non-infringement of claim 10 and sought the appeal.[12]

CLAIM CONSTRUCTION PRINCIPLES

The U.S. Supreme Court, twenty years ago, unanimously ruled that claim construction is a matter of law and judges have the responsibility of construing patent claims.[13] Since then, Markman hearings have been a mainstay of patent infringement cases.

In a Markman hearing, the parties present their disputes regarding the meaning of patent claim terms. “Claim construction is a matter of resolution of disputed meanings and technical scope, to clarify and when necessary to explain what the patentee covered by the claims, for use in the determination of infringement.”[14] Thus, the court considers the parties’ arguments and ultimately issues a claim construction order that addresses the meaning of disputed terms.

But “[claim construction] is not an obligatory exercise in redundancy.”[15] Claim terms are generally given the ordinary and customary meaning understood by persons of ordinary skill in the field at the time of the invention.[16] But when the patentee places a different meaning on a claim term, claim construction is especially appropriate.[17]

“[T]here is no magic formula or catechism for conducting patent claim construction.”[18] Rather, the courts consider different sources of information. The patent specification is the single best guide to the meaning of disputed terms, and additionally, prosecution history can often inform the meaning of patent claim language.[19] These sources of information reflect the patentee’s own views and are referred to as “intrinsic evidence.” Significantly, intrinsic evidence can reveal that the inventor or patentee limited the meaning of a claim term or disavowed certain scope from its claim coverage.[20] In relying on intrinsic evidence in construing claims, however, courts are cautioned not to import into the claims any limitations that are described in the specification but are not required by the claims.[21]

“SHORT SEAL” SEALED THE CASE

The only issue for appeal was whether the district court correctly construed the term “short seal” in the claims based on the intrinsic evidence.[22] If the claim construction was correct, then API would not be an infringer.

The district court did not interpret “short seal” to have customary and ordinary meaning.[23] Rather, determining that Poly-America had limited the meaning of “short seal,” the district court construed “short seal” to mean “a seal for securing the elastic drawstring, which seal is located adjacent to a side seal, and that is not substantially aligned with the side seal, but extends inwardly from the interior edge of the side seal.”[24] The Federal Circuit affirmed this construction as correct.[25]

The Federal Circuit reviewed the intrinsic evidence and noted several indications that supported the construction. Specifically, the Federal Circuit noted:

The specification distinguished the prior art on the basis of extended short seals. The specification explained that prior art trash bags did not have extended short seals, and the use of extended short seals is an improvement upon prior art trash bags.

The specification characterized “the present invention” as having extended short seals. The “Summary of the Invention” section states that: “[E]mbodiments of the elastic drawstring bag contemplated by the present invention have an upper opening with a width that is less than 97% of the width of the rest of the bag (by virtue of the extended short seals).” Moreover, col. 6, lines 11-15 of the ’308 Patent states that: “it is important to note that one of the characteristics of the present invention is a reduction in the upper width 152 (when the bag is in a relaxed state) of the bag 100 resulting from the extended short seals 120.”

All drawings of the short seal show the short seal extending inwardly from the interior edge of the side seal, except the drawing labeled as prior art.

All descriptions of the disclosed short seal state that it reduces the upper width of the bag relative to the width of the bag.

Lastly, the patentee relied on the extended short seal to obtain the ’308 Patent. The patentee argued in prosecution that the independent claims all require an opening width that is less than the width of the bag, and the cited prior art did not have such a feature. The Examiner allowed the application based on this feature of the claims.

In short, the patent specification and prosecution history of the ’308 Patent were all consistent in characterizing the extended short seal as a significant feature of the patent.

The Federal Circuit saw nothing to indicate that the patented claims could have non-extended short seals, and quickly dismissed Poly-America’s arguments against the construction.[35] For example, Poly-America argued that independent claim 10 did not include any dimensional language, so construing claim 10 to include a dimensional limitation improperly imports a limitation of the specification into the claim.[36] The Federal Circuit rejected this argument because all drawings and descriptions of Poly-America’s short seal had short seal extending inwardly from the side seal, so the court was not limiting the short seal of claim 10 to one alternative over another; that is, no other alternatives were disclosed for the short seal.[37] Poly-America also argued that adopting the district court’s construction of “short seal” would result in claims 10 and 13 being redundant, and this indicated that the construction was incorrect.[38] But the court determined that claims 10 and 13 were not redundant under the district court’s construction and rejected this argument.[39]

Notably, Poly-America never argued that it invented non-extended short seals. Presumably, Poly-America could not make this argument because the intrinsic evidence showed that non-extended short seals existed in the prior art.[40] Thus, Poly-America’s suit looked like an effort to extend the ’308 Patent’s coverage to the prior art, and this may have contributed to the claim construction and outcome here.

PRACTICAL LESSONS

Poly-America was not accorded the scope it sought for claim 10 of its ’308 Patent in large part because of the patent specification, as explained above. Consideration of claim scope begins with patent application drafting, and several lessons or reminders from this case are worth noting regarding protection of claim scope in patent application drafting.

If it is necessary to characterize the prior art in the specification, it should be done generally and briefly. And if there is discussion about perceived problems with the prior art, care should be taken to not tie that discussion to any part of the claimed solution. As shown by this case, the ’308 Patent’s focused discussion of the prior art gave API ammunition to frame the claim construction debate in its favor.

In the drawings, if a figure applies to the prior art but also applies to certain embodiments in the patent application, the figure should not be labeled as prior art. Consider not having any drawings that illustrate only the prior art.

In the specification, rather than using the phrase “the present invention” or the like, consider instead using phrases such as “the present disclosure” or “the disclosed technology.” As shown by this case, statements about “the present invention” carry a great deal of weight in claim construction.

In the drawings and the specification, consider illustrating and describing different embodiments of the most significant features. In this case, the court rejected Poly-America’s argument that limitations were imported into the claim because all embodiments showed the same type of short seal.

In the claims, consider expressly reciting aspects of the most significant features that may not be evident, such as relationships between different claim elements. Relying on claim differentiation principle is not a sure bet, as shown by this case.

A patent is by no means an inexpensive endeavor, but it is one than can pay off if claim scope is appropriately protected. More care and investment in the patent application drafting process can go a long way to realizing a patent’s full value.